function CEP = cep_cal2(alpha,theta)
alpha1 = alpha*pi/180;
alpha2 = pi - alpha*pi/180;
theta = theta*pi/180;
r1 = 10;
r2 = 10;
CEP = 1000*0.75*sqrt(r1.^2.*theta.^2 + r2.^2.*theta.^2)./abs(sin(alpha2-alpha1));
end

